Comparison of peracetic acid and bacteriophage application by vascular rinsing on Salmonella reduction in lymph nodes of goat carcasses

The ability of carcass vascular rinsing supplemented with bacteriophage (BP) and peracetic acid (PAA) to reduce Salmonella in lymph nodes (LNs) from experimentally infected goats was determined. Cull dairy goats (n = 60) were randomly assigned to a control (CN, nonrinsed) and two vascular rinse treatments: BP and PAA. Goats were inoculated intradermally with Salmonella Enteritidis and slaughtered after a 7-day incubation. Vascular rinsing was performed postexsanguination via a catheter in the heart. Carcasses were skinned, eviscerated, sprayed with 5% lactic acid, and chilled (2°C) overnight. The superficial cervical, popliteal, medial iliac, and subiliac LNs were collected aseptically for Salmonella enumeration and phage titer determination. The longissimus dorsi (LD) and semimembranosus muscles were also excised, and stored for 1, 4, and 7 days for meat surface color measurements. PAA-treated carcasses showed lower (p < 0.05) temperatures and pH values within 8 h postmortem compared to CN and BP. The average counts of Salmonella in the LNs associated with PAA (3.4 ± 1.3 log CFU/g) were significantly lower compared to CN (3.8 ± 1.1 log CFU/g), with the lowest load observed in medial iliac LNs (2.7 ± 1.5 log CFU/g). Substantial phage titers were detected in LNs from BP-treated carcasses (7.0 ± 0.91 log PFU/g), and no differences were observed in Salmonella counts in BP compared to CN. The meat samples obtained from PAA-treated carcasses exhibited lower redness (a* values) and deoxymyoglobin in the LD (p < 0.05) but showed no differences in lightness or oxymyoglobin compared to BP and CN. Vascular rinsing has the potential to suppress Salmonella in the LNs with other antimicrobials and chemicals with different combinations and concentrations.

Practical Application

This study investigates a method to control Salmonella in goat meat by rinsing carcasses with peracetic acid (PAA) or bacteriophages through the bloodstream after slaughter. The findings suggest that PAA can mitigate Salmonella levels in lymph nodes, potentially improving meat safety. While bacteriophage treatment did not significantly affect the bacterial count to observe differences with the control group, vascular rinsing could still be promising with different antimicrobial combinations. This research would help meat processors enhance food safety measures, reducing the risk of Salmonella contamination in meat products.